In the construction of a dwelling or commercial building, it is common to locate electrical outlets along the bottom portions of walls in the building. It is also common to locate electrical switches at a convenient access height on the walls adjacent to doors and other openings. Such electrical outlets and switches are commonly installed within open front rectangular electrical service boxes embedded within the wall. In modern construction, these utility or service boxes typically are made of plastic. The boxes are attached to vertical studs of the framed-in walls before sheet rock or another wall covering is applied to the wall.
Most building codes in force in this country require that electrical outlets be located a standard distance up from the floor, usually 12 inches. Such codes also usually require that electrical switches be located a standard distance from the floor, usually 48 inches. It is important that these guidelines be followed when constructing a building to ensure that the building inspector will approve the electrical roughing-in done by the contractor or electrician.
In addition to the distance of electrical outlets and switches from the floor, construction codes and practices also require that the front rims of the electrical utility boxes housing the switches and outlets protrude outwardly from the sides of studs to which they are attached so that they will extend through holes in the sheet rock to a position substantially flush with the front surface of the sheet rock. This insures that the bare edges of holes formed in the sheet rock to accommodate these switches and outlets are covered by the walls of the utility box. It also important that the utility box, when attached to a stud, be plum with the stud and not cocked or canted from top to bottom. If the utility box is not plum, one of its ends might protrude outwardly from the sheet rock surface with the other end recessed too far inwardly. Such a condition could be dangerous and might not be approved by a building inspector. In addition, utility boxes have threaded screw posts that receive the screws that mount electrical outlets and switches in the boxes. If the boxes are not plum, it can be difficult to thread these attachment screws into the screw posts of the utility boxes.
In the past, electrical utility boxes have been mounted to studs of a framed-in wall manually by carpenters and electricians. Generally, a carpenter will simply measure and mark the position of each box, whereupon the box will be applied manually against the inside surface of a stud. The carpenter then usually eye balls or measures with a scrap piece of sheet rock the protrusion of the front rim of the box from the side of the stud. The box is then held with one hand while nails fastening the box to the stud are driven by hammer with the other hand. Obviously, this manual method of roughing-in electrical boxes is time consuming, not economical, and can result in substantial errors in placement and orientation depending upon the skill of the particular carpenter or electrician installing the boxes. It is difficult when using this manual method to position the boxes accurately so that they are plum with the studs to which they are fixed.
Some attempts have been made to provide tools or gauges for positioning electrical utility boxes accurately within a wall. One example of such an attempt is illustrated in U.S. Design Pat. No. 250,255 of Douglas et al. While there is no discussion in this patent of the use of the device shown therein, it is presumed that the electrical box setting gauge disclosed in this patent would be placed on the floor with an electrical utility box mounted on the U-shaped bracket at the top of the gauge. With the gauge and utility box so positioned, the box would be nailed to the stud.
While the device of Douglas et al. appears to be a step in the right direction, it nevertheless appears to have problems and shortcomings inherent in its design. For example, the bottom of the gauge, which apparently could rest on the floor during use, is narrow and does not provide sufficient rotational stability for the gauge. In addition, all of the surfaces of this gauge which bear against the floor and against the stud are below the utility box, thus resulting in inadequate stability for the electrical box when the electrician nails the box to a stud. Also, there is no means on the gauge of Douglas for aligning the gauge in the proper vertical orientation against the stud before the electrical utility box it is attached to a stud. The user of the Douglas device apparently would have to eyeball the vertical alignment of the device before nailing the box to the stud. The inherent instability of the Douglas device likely would result in wobbling or movement of the gauge during use, thus tending to degrade the reliability and accuracy of the gauge. Additionally, the gauge of Douglas appears to be nonfunctional since there is no provision on the box support bracket for accommodating the inwardly protruding screw posts and wire securing mechanisms on the interior of common utility boxes.
Thus, there exists a need for an improved jig usable by carpenters and electricians to rough-in electrical outlet boxes in the framed-in walls of a building structure. Such a jig should be inherently very stable during use so that any movement of the jig as the boxes are being attached is eliminated. The jig should be simple and convenient to use and should ensure that utility boxes are fixed to the sides of studs at precisely the proper height above the floor, with precisely the correct protrusion of the front rim of the box from the stud, and with the box aligned plum with the stud. The jig should further be economical to produce in quantity, rigid enough to withstand commercial use, and should be equally usable to place single electrical utility boxes or multiple ganged utility boxes. It is to the provision of such a jig that the present invention is primarily directed.